[dv3andrs]

If power is getting all the way to the back of the trailer, that would lead me to believe it's a light assembly issue. With no fuses popping than there should be no short through that length of wire. I know you said you installed a new light assembly, did you possibly gain a bad bulb with the new assembly? Otherwise I would pull the wiring back off the new assembly and double check the wiring there. Good luck! I always hate chasing wiring gremlins. If you have a new relay or can swap it with another one try that as well.

 

[DougL58]

I was going to try swapping the two blue relays but I do not know 1) if they are interchangable and 2) if they each control left and right seperatly. I'm assuming this is a good step but wanted confirmation before I try it.

 

[JohnS]

I say just do it

 

[Nightstalker 6]

bad ground on that single light fiture.

 

[DougL58]

bad ground on that single light fiture.

I removed the light assembly from the trailer, have the power wire connected and then touch it to another ground spot on the trailer. Same issue, as soon as the circuit is complete, the power reading drops to .4. Same with both the new and old light assembly and testing on different ground spots.

 

[Carbeaux]

Swap the relays. Won't hurt anything. It's possible it's the relay, but I think it's unlikely.

 

[bestatchess]

Set meter to measure resistance (ohms), disconnect wires to trailer light assemblies, measure resistance across terminals of light assemblies.

BTW: Power = watts. Voltage = volts. Power is not the same thing as voltage. Current = amps. Current is not the same thing as voltage. Power (watts) = V (volts) x I (current measured in amps). V (volts) = I (amps) x R (resistance measured in ohms).

 

[DougL58]

Swapped relays - problem followed the relay. Passenger now works. Drivers does not. Not going to wait for the dealer... NAPA $9...

Thanks for all in input !

 

[Dan04]

Where are the relays?

My trailer running lights work, but my driver side brake light and directional do not work on my 04 Titan. I have an 05 Titan also and all works well when connected to this truck.

I have tested at the receiver on the truck and the left blinker is dead. I've had intermittent problems before but it always seemed a big enough bump in the road would fix it.

 

[IGotLost]

Relays are under the hood. Passengers side, close to the firewall. Look for a black box.

 

[DougL58]

Yes, it was the relay. You can get aftermarket parts from NAPA for 6 or 7 $.

 

[beeradster]

My guess is that the relay is putting out a ghost voltage. You can read it on your meter but when you put it under load the voltage drops and doesn't do any work.